need help in steps, thank you

(b) Scores are normally distributed with mean =100 and standard deviation : 15. Which, zscore = (value of a piece of data mean)/ standard deviation. (i) What is the percentage of people below score 100? (2 marks) (ii) What is the IQ score of people at the point below two standard deviation? (2 marks) (iii) What is the IQ score of people at the point with z-score : 1.5? (2 marks)